Richard smith



. '2Sh eetsSheet 1,5 R. $MITH. DOCTOR FOR CA-LENDER ROLLS.

- No, 497,610. Patented 'May 16, 1893.

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- R. v SMITH. v DOCTOR FOR GALENDEB ROLLS. No. 497,610. v Patented May 16, 1893.

jWZi/wsses; flue/Zion NITED STATES PATENT OFFICE.

RICHARD SMITH, OF SHERBROOKE, CANADA.

DOCTOR FOR CALENDER-ROLLS.

SPECIFICATION forming part .of Letters Patent No. 497,610, dated May 16, 1893.

Application filed August 3, 1891- To all whom it may concern.-

Be it known that I, RICHARD SMITH, a citizen of the Dominion of Canada, residing at Sherbrooke, in the county of Sherbrooke and Province of Quebec, Canada, have invented certain new and useful Improvements in Doc- .tors for Calender-Rolls; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

This invention relates to a pneumatic device for leadingpaper through calender rolls in the process of its manufacture, as it is delivered from the paper-making machine in a continuous web.

My invention may be considered as relating to, and an improvement upon that shown in the invention embodied in United States Letters Patent No. 327,031, issued in my name on the 29th day of September, 1885.

My invention in the present instance consists in improvements as indicated by the claims hereunto appended, in the construction of the doctors or shields, which are alternately disposed upon opposite sides of the several rolls composing the stack.

In carrying my invention into effect I provide a series of depending hollow fingers perforated on their inner faces throughout their. lengths and attached to a hollow tube pivotally mounted in suitable bearings. This tube conveys the air to the depending hollow perforated fingers'and as the air escapes through the apertures and impinges against the web of paper passing around a roll the paper is held by the air pressure against the surface of the roll about which it is now passing more closely than by the devices heretofore in use. Thus the paper is held against, and travels at the same rate of speed as the rolls, and less broken is made, since the web or sheet is prevented from doubling back or slipping as it frequently does. Hence this device is especially adapted for sh eet-calenders or for supercalenders.

Other peculiar features of construction will be hereinafter more fully explained.

The drawings presented show in Figure 1, a vertical sectional elevation endwise of the Serial No. 401,501. (No model.)

stack. Fig. 2 is a side elevation with a portion of one roll removed to show the perforated surface of the doctor fingers. Fig. 3 is a cross-section vertically through a doctor and its co-operating rolls enlarged. Fig. 4 is a sectional elevation of the journal of a doctor. Fig. 5 is an end view of the journal support and doctor. support with end of doctor disengaged. Fig. 7 is a cross-section and Fig. 8 a front elevation of a doctor. a preferred construction of doctor, and Fig. 10 is a front elevation of the same. Fig. 11 is a vertical section on line ma2 of Fig. 4:.

In said drawings A A represent the housings in which are mounted a series of calender rolls B B B adapted to be suitably op-.

erated and forming part of a paper-making machine. In connection with these rolls is employed a series of doctors, or deflecting shields, which are employed as guides by which to automatically lead a continuous traveling endless paper Web, or sheet, between and partially around each roll in a series of rapidly revolving rolls, which comprise the calender stack so called. In the present instance said doctors are shown as pivotally mounted upon the vertical portions of a wind, or air pipe system, shown at O O or otherwise. Furthermore said doctors are reversely disposed upon opposite sides of each alternate roll in the stack, as shown,and said doctors are designated as D D D and partially inclose one roll, while they are in contact with the roll next above. Hence the paper, as it passes between two rolls is met by the doctor and deflected down about the partially inclosed side of one roll, and directed between the next two rolls where it is again guided by Fig. 9 is a cross-section of a second doctor, and so on through the stack. The doctor embodying my invention comprises a tube a provided with an air passage 1), said tube being of about the length of a roll, and preferably extending in a horizontal direction parallel with the roll and being pivotally mounted upon suitable supports. Each I to and embracing the pipe 0, the tubes a having spring connections with the said plates F, as will hereinafter be described. Attached to said tube is a series of curved pendent fingers or deflectors c which inclose one side of the roll, (non-contiguous thereto) and preferably are of a curvature concentric with that of the roll with which they co-operate. In my present improvements these fingers or guides are spring-actuated, and are mounted and operated as follows: The closed end of the doctor is formed with a transverse slot f, which engages a corresponding rib 9 cast upon a bearing block E. The latter is further provided with a semi-annular rim h of a thickness to afford this end of the doctor a good support. By omitting the upper part of the rim the doctor can easily be removed from its bearings. The rear side of the block E is cast with a cireularhub or boss 1., which enters a This recess conrecess j in a fixed plate F. tains a coiled spring 7c, one end of which is to be attached to the boss z' and this spring is so;

disposed that its tension shall be exerted to press the upper part of the d ctor against its- It is to be understood that the plate F, is a fixture, and may be bolted to the hous ings A A or other suitablepart of the stack.

In Figs. 7 and S the doctors are represented; as composed of the main air tube ct to which. are affixed at regular intervals a series ofv curved pendent fingers as hereinbefore de-;

roll.

scribed. In such event the upper ends alone of said fingers are in contact with the surface of the roll.

In Figs. 9 and 10 I have shown a construction in which a straight thin steel bar sis attached to the upper extremities of said fingers. Thus the latter are strengthened and braced, while the bar rests for its entire length upon the surface of the roll. An ob vious advantage in the use of this bar 3 is, that it prevents any small substance from sticking to the surface of the roll, and thereby injuring the paper. This might occur in the use of a doctor constructed as in Fig. 7, since the foreign particle might be located between two of the fingers and not being touched by them, would adhere to said roll and cause trouble.

The operation of this improved doctor is as follows assuming a doctor is in position: The endless web or sheet is directed between two rolls; as it emerges upon the other side it meets the doctor or shield, when it is deflected downward. But now in lieu of passing along impelled merely by frictional contact with the surface of the roll, said paper is subjected to the pressure arising from the air escaping through the numerous apertures e in the fingers. Hence it is held snugly against the roll; no slip occurs and the result is that the paper passes along with a fair tension upon it. Thus less waste is incurred, when mending up, this is especially desirable in super-calendering.

What I claim is 1. A deflector or doctor composed of a tube to which is attached a series of dependent hollow fingers perforated throughout their lengths upon their inner faces and provided with apertures opening into the said tube, combined with an air supply system whereby a flow of air may be directed outwardly and continuously through said fingers, substantially as and for the purposes set forth.

2. The combination with an air supply system and two revoluble rolls, one partially inclosed by but non-contiguous to, and the other in contact with a deflector or doctor, of a doctor pivotally mounted and composed of a tube, and a series of hollow fingers or guides attached to said tube and perforated throughout their lengths on theirinner sides, sub stantially as described.

3. In combination with a series of continuously revolving rolls, and an ail-supply system, (the pivotal deflectors or doctors oppositely and serially disposed on either side of said rolls, said doctors alternating near the meeting surfaces of the rolls, and being each composed of a tubular back and a series ofhollow fingers perforated throughout their lengths on their inner sides and being thus adapted to direct a continuous supply of air against that part of the roll inclosed, substantially as specified and described.

4. A doctor or deflector composed of a tubular back and a series of pendent hollow fingers provided with apertures or air openings throughout their lengths on theirinner sides, combined with a straight bar secured to the upper extremities of each of said fingers and adapted to come in contact with a revoluble roll, and with an air supply system, substantially as and for the purposes herein described.

5. The combination 'with an air supply system and two revoluble rolls, B B, of a pivoted doctor composed of a tube provided with hollow perforated curved fingers c and an end slot f, the spring-actuated bearing E provided with a rib g to enter said slot, and a spring to operate the bearing and hold the doctor in contact with one of the rolls, substantially as stated.

In testimony whereof I aflii: my signature in presence of two witnesses.

RICHARD SMITH.

Witnesses:

H. E. LODGE, FRANCIS O. STANWOOD. 

